Desiccating apparatus



Aug. 22, 1933. w, s, BOWEN nsszccmme APPARATUS 3 Sheets-Sheet 1 Filed Jan. 6, 1930 duk ATTORNEY INVENTOR l/i/H/mm 5,0076 50w? BY Aug. 22, 1933.

'w. s. BOWEN 1,923,659

DES ICCATING APPARATUS Filed Jan. 6, 1950 3 Sheets-Sheet 2 BY ml/zbrn .Zaenrer Bowen ATTORN EY Aug. 22, 1933. w. s. BOWEN DESICCATING APPARATUS 3 Sheets-Sheet 3 Filed Jan. 6, 1930 (IA ATTORNEY Patented Aug. 22, 1933 UNITED STATES PATENT OFFICE DESICCATING APPARATUS William Spencer Bowen, Westfield, N. J.

Application January 6, 1930. Serial No. 418,685 2 Claims. (Cl. 159-4) The invention relates to the art of spray drying, being applicable to therecovery of solids from liquids in which they are dissolved or suspended or from slurries; and more particularly to apparatus wherein the solid-containing liquid is introduced in finely divided state, together with a suitable desiccating gaseous medium, into a suitable closed chamber.

The invention has for its object to so introduce the solid-containing liquid into a tower, or

other closed chamber, and control the flow of the gaseous desiccating medium therethrough in such.

a manner that the said liquid in finely divided condition will be conformed to a more or less flame-shaped stream, whereby the particles dried by the action are confined portions of the tower sufficiently removed from the inner wall or face thereof to avoidcontact therewith.

A further object of the invention resides in the novel construction and arrangement whereby a multiplicity of these flame-shaped streams or jets may be operated simultaneously within a single chamber without interference.

The invention has for a still further object a novel arrangement for withdrawing the spent gaseous desiccating medium from the far end of the chamber in a manner such that a uniform axial fiow thereof is attained therethrough.

In carrying out the invention, provision is made, as at the top of a tower of suitable dimensions, to introduce at one or more points the solidcontaining liquid in finely divided condition by spray-producing means, such as centrifugal disintegrating devices, which are designed to project 'the liquid in extremely finely divided condition as a plane of spray and-in a direction substantially radial of the tower. The desiccating medium at a suitable velocity is arranged to be introduced slightly behind the plane of the issuing finely divided liquid about the same and in an axial direction with respect to the disintegrator, that is to say, having a direction of 'fiow substantially at right angles to the direction of projection of conductors l7.

radial disintegrator devices may be arranged symmetrically at the top of the tower and at proper distances apart to avoid interference among the respective resulting jets. Provision has been made, also, to secure a uniform outflow through the bottom of the tower so that the substantially uniform and axial flow of the desiccating medium necessary for conforming and individualizing the respective jets as aforesaid will be insured and maintained throughout the tower.

The nature of the invention, however, will best be understood when described in connection with the accompanying drawings, in which:

Fig. l is a side elevation of one form of desiccatlng apparatus to which the invention is applicable.

Fig. 2 is a fragmentary vertical section through the novel desiccating apparatus and on an enlarged scale.

Figs. 3 and 4 are horizontal sections therethrough taken respectively on the lines 3-3 and 4-4, Fig. 2 of the drawings, and looking in the direction of the arrows.

Referring to the drawings, 10 designates a desiccating chamber as embodied, for example, in a vertical type of desiccating tower, preferably constructed of cylindrical form and of concrete with closed top 11 substantially sealing the tower and having an intermediate diaphragm or closure member 12 displaced somewhat therefrom. This latter closure member is provided, in the present instance, with a plurality of symmetrically disposed circular openings 13, as, for example, a central opening surrounded by four equidistantly spaced openings, making five in all, through the said diaphragm.

The desiccating medium, such as furnace or other gases at the required temperature, is arranged to be introduced into the space between the top 11 and diaphragm 12 through a supply duct l4, whereby a plurality of columnar streams of gaseous desiccating medium will flow substantially vertically'of the tower through the orifices 13 provided in the diaphragm 12. Devices 15, for finely dividing the solid-containing liquid and affording a plane of spray thereof as it is introduced' into the interior of the tower, are mounted in the axis of the respective orifices 13, the liquid being-introduced to said devices through respec-' tive inlet pipes 16 and power for operating the motors for the disintegrating devices through the The said disintegrating devices may embody, for example, a disk 18 of the nature set forth in my prior U. S. Letters Patent No. 1,692,617, and which is adapted to be rapidly rotated to disperse the liquid in a finely divided condition and in a substantially horizontal plane, or radially with respect to the axis of rotation of the disk. I

A said disk, furthermore, and in accordance with the invention, is located at a slight distance only beyond the corresponding outlet orifice 13 for the gaseous desiccating medium; and I have found that adistance approximating 1 to 10 inches and depending on the velocity of the gaseous medium and capacity of the apparatus, gives the desired results. It will be observed that the gaseous desiccating medium entering the interior of the tower 10 through an orifice 13 is in a direction substantially parallel to the axis of the orifice and is in the nature of a more or less cylindrical or columnar stream. In meeting at the proper distance from the point of exit with the radially projected finely-divided liquid, it bends over the spray, more or less as indicated, to conform the same to a flame-shaped stream or jet from which the particles of solid matter as they become dried drop to the bottom of, the tower. The velocity of such incoming stream will be determined not only by the character of the spray but by the kinetic energy required to effect the desired conformation which, in turn, is a function of the mass of the gaseous medium.

The bottom of the tower is indicated at 20, being preferably conically shaped and having a scraper member 21 rotatable thereover for assisting in the removal of the desiccated product through the bottom of the tower and, preferably, together with the spent gaseous desiccating medium. In accordance with the invention, this is accomplished by drawing the samethrough an annular outlet 22, formed between the circumference of bottom 20 and the inner wall of the tower, into a more or less circular channel 23 located immediately beneath the outlet 22 and communicating therewith substantially throughout its entire length. An outlet opening 24 therefrom delivers the product and spent medium into a duct 25 through which it is drawn by suitable suction means such as the fan 26 communicating therewith.

V In order properly to maintain the desired axial and a substantially uniform flow through the tower, provision has been made for establishing a substantially uniform suction at the bottom of the tower; and to this end the more or less circular channel is constructed, furthermore, to be of increasing width as well as of increasing depth toward the final outlet opening 24 so as to induce an outflow at uniform velocity over the bottom edge and through the annular outlet 22. a

Provision is made, moreover, for correcting the outflow velocity at various portions along the annular outlet 22 as by introducing baflle members 28, which are disposed to this end circu larly about the desiccating chamber abovesaid outlet 22. These baflies are in the nature of planks or slides which are adjustably mounted upon inclined supports 29 secured in the wall of the tower 10. The said baflle members are tially equal velocities entirely around the outlet.

This results, furthermore, in continuous entrainment of the dried particles in the spent gaseous medium passing through the channel 23 and prevents thereby deposition of the dried product in any portion of said channel, which deposition might result in objectionable variations of velocity of the gaseous medium.

Proper conformation or symmetrical shape of the finely divided liquid or spray into a stream or streams of a more or less flame shape, as

indicated, will thus be, insured so that there will be no objectionable intermingling or confusion of the different streams and especially no contact of the desiccated product, with the inner wall of the tower 10, thus avoiding adhesion to and building up of a deposit thereon, which necessitates not only'loss of and an inferior product, but requires frequent shut-downs for scraping and cleaning of the tower.

I- claim:

1. Desiccating apparatus for solid-containing liquids, comprising a closed tower, spray-producing means located at the upper portion thereof for discharging the liquid in finely-divided condition into the tower, the said tower being provided at the top with an inlet orifice for a gaseous desiccating medium, a floor at the bottom of the tower to receive the desiccated product and having its circumferencedisplaced from the tower wallto afford an annular outlet opening for the product, an outlet channel below the annular opening, and means connected with the channel for withdrawing the spent desiccating medium and all of the desiccated product through the said annular opening and channel.

2. Desiccating apparatus for solid-containing liquids, comprising a closed tower, spray-producing means located at the upper portion thereof for discharging the liquid in finely-divided condition into the tower, the said tower being provided at the top with an inlet orifice for a gaseous desiccating medium, afioor at the bottom of the tower to receive the desiccated product and having its circumference displaced from the tower wall to afford an annular outlet opening for the product, an outlet channel below the annular opening, bafile means inserted above the annular opening to control the velocity of the desiccating medium through said opening, and

means connected with the channel for withdrawing the spent desiccating medium and all of the desiccated product through the said annular opening and channel. J

WILLIAM SPENCER BOWEN. 

